As an interlayer insulation film for a semiconductor device, there is mainly used an oxide film (SiOx film) prepared by CVD method (Chemical Vapor Deposition method) and so on. An inorganic insulation film, however, can hardly achieve speeding up and upgrade of a semiconductor due to high dielectric constant thereof. Accordingly, organic materials are considered to be used as interlayer insulation films having low dielectric constant. Such organic materials are required to be excellent in heat resistance and electrical properties, and to have low dielectric constant.
As such organic materials, polyimide resins, polyquinoline resins, polyquinoxaline resins and so on have been studied. (For example, see Japanese Patent Application Laid-Open (JP-A) No. 2000-195853.)
However, polyimide resins generally have problems of low heat resistance, high dielectric constant, high moisture absorptivity and so on. Thereby, use of polyimide resins is limited to some semiconductor elements such as a bipolar semiconductor element due to reliability thereof.
On the other hand, polyquinoline resins and polyquinoxaline resins having higher heat resistance, lower dielectric constant and lower moisture absorptivity than polyimide resins are thermoplastic resins and there is a problem accordingly that patterns of the resins may change shape by being exposed to temperatures higher than glass-transition points thereof during semiconductor production.